Reaction apparatus

ABSTRACT

The present invention provides a reaction apparatus which is used for gas-liquid chemical reaction and is capable of producing a target reaction product. The present invention provide a reaction apparatus for conducting a gas-liquid chemical reaction in the state that a liquid is in a continuous phase,wherein its reactor has therein a shear type stirring impeller for dispersing a raw reaction gas or a carrier gas and a film-formed catalyst; and a process for producing a tertiary amine. This reaction apparatus is preferably used to react a primary or secondary amine with an alcohol.

FIELD OF THE INVENTION

The present invention relates to a reaction apparatus wherein afilm-formed catalyst is used to conduct a gas-liquid chemical reactionin the state that a liquid is in a continuous phase, in particular, areaction apparatus which is suitably used when an alcohol and a primaryor secondary amine are used as starting materials to produce thecorresponding tertiary amine.

BACKGROUND OF THE INVENTION

A great number of industrial reactions are conducted in mixing-chambertype reaction apparatus wherein a solid catalyst is made into a slurryand used. The catalyst made into the slurry is made of fine powder. Inthe presence of the catalyst, a reactive gas such as hydrogen or ammoniais brought into contact with a liquid to conduct reaction. When thereaction ends, the catalyst is generally removed by filtration, so as tocollect the reaction product.

However, a catalyst in a slurry form has problems about safety, anincrease in wastes, operability, productivity and so on. For example,one of the problems is a problem that many catalysts are naturallyignitable, thereby causing an anxiety about safety. A second one thereofis a problem that the catalyst generally needs to be removed byfiltration in order to collect a reaction product, thereby makingfacilities therefor and the operation thereof complicated.

An example of a production process which neither needs any mixingoperation, such as stirring or gas bubbling, nor any separation of acatalyst by filtration is a fixed bed process. As the catalyst used inthe fixed bed process, there have been hitherto well-known moldedcatalysts such as pellet-form, noodle-form or tablet-form catalysts. Thecatalysts are each a catalyst wherein a powdery material having catalystactivity is molded into any one of the above-mentioned forms bycompression, extrusion or some other method, thereby forming a structurehaving therein countless pores so as to make the form of bulk compatiblewith a high surface area. The process is disclosed in, for example,JP-A-6-211754.

As a different method for fixing a catalyst, known is a method offorming a thin catalyst layer in a film form inside a reaction field.For example, JP-A-2003-176255 discloses a reactor wherein a catalystmetal is caused to adhere onto the surface of a monolith. Therein, thefollowing advantage is indicated: in a hydrogenating reaction between areactant gas and a reactant liquid, a drop in the pressure inside thereactor is small so that speeds of the gas and the liquid can be madelarge; therefore, the mass transfer therein is further promoted than infixed bed filled reactors of conventional types.

A different reactor using a monolith catalyst is disclosed inJP-A-2003-275577. In order to improve the solubility of a reactant gasinto a reactant liquid, the gas is finely dispersed by the rotation of aturbine impeller fitted onto a housing into which the catalyst is put,and in order to control the convection state of the reactant liquid, abaffle is used. In this way, the selectivity of a hydrogenation reactionfor producing aniline from nitrobenzene is improved.

SUMMARY OF THE INVENTION

The present invention provides a reaction apparatus for conducting agas-liquid chemical reaction in the state that the liquid forms acontinuous phase, provided with a film-formed catalyst and a shear typestirring impeller for dispersing a raw reaction gas or a carrier gas.

The present invention provides a process for producing a tertiary amine,comprising the step of reacting a primary or secondary amine with analcohol in the above defined reaction apparatus.

The present invention further provides use of the above shown reactionapparatus for conducting a gas-liquid chemical reaction in the statethat the liquid forms a continuous phase and a raw reaction gas or acarrier gas is dispersed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an example of a concaveturbine which is a shear type stirring impeller used in the presentinvention;

FIG. 2 is a perspective view illustrating an edged turbine which is ashear type stirring impeller used in the present invention;

FIG. 3 is a front view of a reaction apparatus used in Example 1;

FIG. 4 is an enlarged view of a baffle section of the reaction apparatusillustrated in FIG. 3;

FIG. 5 are views illustrating an edged turbine used in Example 1, andFIGS. 5(a) and FIG. 5(b) are a front view thereof and a plan viewthereof, respectively;

FIG. 6 is a perspective view illustrating a propeller impeller used inComparative Example 1;

FIG. 7 is a front view of the propeller impeller used in ComparativeExample 1; and

FIG. 8 is a front view of a reaction apparatus used in ComparativeExample 1.

Reference numerals in the drawings are explained.

-   1 concave turbine-   11 edged turbine-   2 reactor (separable flask)-   3 film-formed catalyst-   4 casing-   5 baffle-   6 glass tube-   7 propeller blade

DETAILED DESCRIPTION OF THE INVENTION

A reaction manner as described in JP-A-6-211754 solves many problemsabout the handling of a catalyst or wastes, but cannot be applied tomany reactions on the basis of technical problems. One of the problemsis that in reactions followed by the generation of heat, a problem iscaused in the control of a rise in the temperature of the whole and thegradient of the temperature. Another problem is caused in thedistribution of the liquid and gas in a reactor. An insufficientconversion ratio and a localized concentration gradient are oftengenerated so as to promote a side reaction.

In JP-A-2003-176255, a static mixer is used in order to distribute gas.It is difficult to apply or divert a mixing-chamber type reactor used ina slurry catalyst system reaction, as it is, to this technique.

In JP-A-2003-275577, the convection of a liquid is positively performed.Therefore, this technique has a problem that the time when gas isretained in a catalyst layer is decreased so that the time when the gasis dissolved into the liquid becomes short.

The present invention provides a reaction apparatus which is used forgas-liquid chemical reaction and is capable of producing a targetreaction product with a high yield by a simple process.

According to the reaction apparatus of the present invention, a targetmaterial can be obtained with a high yield by a simple process whereinno catalyst-separating-operation is necessary.

The gas-liquid chemical reaction of the present invention means achemical reaction, such as addition reaction, hydrogenation reaction ordehydrogenation reaction, which is conducted by blowing a raw reactiongas or a carrier gas into a place where a liquid is in a continuousphase.

The film catalyst used in the present invention means a catalyst in theform of a thin film having a thickness of 1 mm or less, which isdifferent from any conventional irregularly-filled type having a size ofabout several millimeters. The process in raw reaction materials and areaction product are transferred inside the catalyst is controlled bydiffusion. When the distance therefor is made short to 1 mm or less,mass transfer between the inside and the outside of the catalyst can bepromoted so as to suppress any excessive reaction of reactionintermediate materials inside the catalyst. In particular, the thicknessis preferably 100 μm or less, more preferably 50 μm or less. The lowerlimit of the thickness is preferably 0.01 μm or more, more preferably 1μm or more in order to keep the strength of the catalyst layer surelyand give endurance in strength thereto.

About the structure of the film-formed catalyst, it is necessary thatthe structure is a structure wherein the supply of raw reactionmaterials to the body of the catalyst and the collection of a productfrom the catalyst body can easily be performed. In order to advance thereaction effectively, it is desired to make the surface of the catalystbody, where the supply of the raw reaction materials and the collectionof the product are performed, as wide as possible. In order to attainthis requirement, the following is preferably used: an object whereinthe film-formed catalyst is fitted onto the inner wall face of a setwherein tubes having an inside diameter of several millimeters toseveral tens of millimeters are bundled or a honeycomb structure havinga cell density of several tens to several hundreds of cells per squareinch; or the like.

In order to make the film-formed catalyst into the above-mentionedvarious structures, for example, a method of molding a catalyst activematerial itself into a honeycomb-form structure and other methods can beconsidered. From the viewpoint of making a thin catalyst layercompatible with a high mechanical strength, it is preferred to fix thefilm-formed catalyst onto the surface of a support. Examples of themethod therefor include a method of forming a coating layer containing acatalyst active material onto the surface of a metal or a support havingrigidity, in the form of a tube, flat plate, honeycomb or the like,thereby preparing the film-formed catalyst. As the coating method atthis time, a method known in the prior art can be used. Examples thereofinclude physical vapor deposition methods such as sputtering, chemicalvapor deposition methods, a method of impregnation from a solutionsystem, and various coating methods such as blade, spray, dip, spin,gravure, and die coating methods, using a binder.

The internal structure of the film-formed catalyst depends largely onthe kind of the active material constituting the catalyst body, themethod for producing the catalyst body, and so on, and may be made of adense continuous phase or may be porous. For example, in the case of athin film formed on the surface of a support by sputtering, chemicalvapor deposition or the like, the thin film can be made into a densecontinuous phase. In the case of using a powdery active material to forma film onto the surface of a support by wet or dry coating or some othermethod, the film can be made porous.

The film-formed catalyst may contain therein a binder for fixing theactive material therein to form the film-formed catalyst body. Thebinder itself does not act as an active material. The binder may be anypolymer or inorganic material that has not only a property for bindingthe active material particles or binding the binder to the supportsurface but also chemical resistance, heat resistance and other naturesfor resisting reaction environment and producing no bad effect to thereaction system. Examples thereof include cellulose resins such ascarboxymethylcellulose and hydroxyethylcellulose, fluorine-containedresins such as poly(tetrafluoroethylene) and poly(vinylidenefluoride),urethane resins, epoxy resins, polyester resins, phenol resins, melamineresins, silicone resins, and other polymer compounds; and sols ofinorganic compounds such as silica and alumina.

As the type of the reactor into which the film-formed catalyst isfitted, various types, including types known in the prior art, can beadopted if the types make it possible to carry out stirring with astirring impeller.

The distribution and supply of a gas into the film-formed catalyst layerare performed while fine air bubbles are formed with the stirringimpeller. At this time, in order to make the retention time of the gaslong, it is desired not to force out the liquid in the axial directionor the circumferential direction by the stirring, so as to suppress theconvection of the liquid with the stirring impeller. For this purpose,in the present invention, a shear type stirring impeller is used whichmake the following possible: fine air bubbles are formed by shear force;the interfacial area between the gas and the liquid is increased topromote diffusion; and the retention time of the air bubbles is madelong since rising speed of the air bubbles becomes small.

The shear type stirring impeller herein means a stirring impeller havinga relatively high shear power for the jetting-out power thereof.Examples thereof include a flat turbine, a concave turbine, and an edgedturbine. The concave turbine and the edged turbine are preferred. Theconcave turbine is a stirring impeller 1 defined in U.S. Pat. No.579,180and others, as illustrated in FIG. 1. The edged turbine is a stirringimpeller 11 having such a form that blades are fitted substantiallyperpendicularly to a disc and further the angle of the blades to thecircumferential direction is from 0 to 30°, and is specificallyillustrated in FIGS. 2 and 5. It is desired that the positions of theblades are below the lower end of the catalyst layer in order to supplythe gas effectively to the catalyst layer.

As the method for supplying a gas to be dispersed by stirring to thefilm-formed catalyst layer, there can be adopted various methods,examples of which include methods known in the prior art, such as asingle tube type sparger and a ring type sparger. A supply opening forthe gas may be positioned in any one of the upside, the downside and theside of the impeller. In order to make the gas minute effectively anddisperse the gas, it is preferred that the gas is blown out toward thedownside of the impeller.

As illustrated in FIG. 3, the method for fitting the film-formedcatalyst into the reactor is preferably such an arrangement in adoughnut form that the film-formed catalyst 3 is fitted to the vicinityof a wall surface of the reactor 2. In the arrangement, it is preferredto use a casing 4 for fixing the catalyst. An inner cylinder of thecasing is preferably provided with a baffle 5 so that the gas is inducednot to flow through the central region of the reactor where the catalystis not placed and the liquid is suppressed from convection. Furthermore,it is preferred to cause this baffle 5 to have an escalation angle fromthe central region toward the wall face of the reactor, as illustratedin FIG. 4, in order not to cause any retention of the gas.

The reaction apparatus of the present invention can be used suitably forreaction for producing a tertiary amine from a primary or secondaryamine and an alcohol.

The alcohol as the starting material used to produce a tertiary amine ispreferably a linear or branched, saturated or unsaturated aliphaticalcohol having 6 to 36 carbon atoms. Examples thereof include hexylalcohol, octyl alcohol, lauryl alcohol, myristyl alcohol, stearylalcohol, behenyl alcohol and oleyl alcohol; mixed alcohols thereof;Ziegler alcohols obtained by the Ziegler process; and oxo alcohols andGuerbet alcohols obtained by the oxo process.

The primary or secondary amine used when a tertiary amine is produced ispreferably an aliphatic primary or secondary amine. Examples thereofinclude methylamine, dimethylamine, ethylamine, diethylamine,dodecylamine, and didodecylamine.

The corresponding tertiary amine obtained from the alcohol and theprimary or secondary amine, which are starting materials, is a substancewherein the hydrogen atom(s) bonded to the nitrogen atom in the primaryor secondary amine is/are substituted with one or more alkyl and/oralkenyl group(s) derived from the alcohol. For example, thecorresponding tertiary amine obtained from lauryl alcohol anddimethylamine is N-dodecyl-N,N-dimethylamine, and is distinguished fromN,N-didodecyl-N-methylamine and N,N,N-tridodecylamine, which are each atertiary amine as a byproduct resulting from reaction with methylamineand ammonia, both of which are produced by disproportionation ofdimethylamine.

The active material which constitutes the film-formed catalyst is notlimited to especial kind, and may be any known active material. In thecase that an alcohol and a primary or secondary amine are used asstarting materials to produce the corresponding tertiary amine, aCu-based material or the like can be preferably used. Examples thereofare Cu alone, or metals made of two or more components wherein one ormore transition metal elements, such as Cr, Co, Ni, Fe and/or Mn, is/areto Cu. Examples thereof are also substances wherein these are furthercarried on silica, alumina, titania, zeolite or the like.

When a tertiary amine is produced, it is desired that the pressure inthe system is not remarkably high over normal pressure. The reactiontemperature is varied dependently on the kind of the catalyst, and thereaction is conducted preferably at a temperature of 150 to 300° C. Inthe case that byproduct water produced in the process of the reaction isdischarged out of the reaction system, the advance of the reaction canbe promoted and the activity of the catalyst can be kept.

The use of the reaction apparatus of the present invention makes itpossible to yield a target reaction product with a high yield, in agas-liquid chemical reaction in the state that a liquid is in acontinuous phase, by a simple process.

EXAMPLES

Then examples according to the present invention will be explained.These examples are intended to describe preferred embodiments of thepresent invention and are not intended to be limiting of the invention.

Production Example 1 Production of a Film-formed Catalyst

A film-formed catalyst made of a three-component copper-nickel-rutheniumcatalyst active material and carried on synthetic zeolite was preparedas follows.

Synthetic zeolite was charged into a flask having a volume of 1 L, andsubsequently thereinto was put a solution wherein copper nitrate, nickelnitrate and ruthenium chloride were dissolved in water in such a mannerthat the ratio by mole between the metal atoms therein would satisfy:Cu:Ni:Ru=4:1:0.01. While the solution was stirred, the temperaturethereof was raised. An aqueous 10% by weight Na₂Co₃ solution wasdropwise added slowly at 90° C. to the solution while the pH thereof wascontrolled into the range of 9 to 10. The solution was ripened for 1hour, and subsequently the resultant precipitation was filtrated, washedwith water, dried at 80° C. for 10 hours, and then calcined at 600° C.for 3 hours to yield a powdery catalyst active material. The ratio ofmetal oxides in the resultant catalyst active material was 33% byweight, and the ratio of synthetic zeolite was 67% by weight.

To 31 parts by weight of the catalyst active material were added 38parts by weight of a phenol resin (PR-50626 manufactured by SumitomoBakelite Co., Ltd.; solid content: 44 parts by weight), and then themixture was put together with 31 parts by weight of acetone into a 50-mLwide-mouthed polyethylene bottle (AS ONE Corporation). The resultant wasmade into a paint with a paint shaker. This paint was applied onto acopper foil (thickness: 35 μm, 12 cm×300 cm) as a support with a barcoater, and then at 150° C. drying and the hardening of the resin wereperformed for 15 minutes to fix the film-formed catalyst 10 μm inthickness onto both surfaces of the copper foil. The weight of thefilm-formed catalyst excluding the copper foil was 5.6 g (including theweight of the binder).

Example 1

The reaction apparatus illustrated in FIG. 3 was used to conduct thefollowing reaction.

A part of the film-formed catalyst obtained in Production Example 1 werefolded into waved plates, and the wave plates and the remaining flatplates were alternately wounded in layers and arranged into the form ofa doughnut having an inside diameter of 80 mm and an outside diameterequal to the inside diameter (inside diameter: 130 mm) of the 2-Lseparable flask 2 made of glass. The volume of the region 3 into whichthe film-formed catalyst was fitted was 660 mL. The film-formed catalystwas thus formed to have plural channels being continuous through theaxial direction of the separable flask 2. Each channel had across-section area of about 0.1 cm². Into the separable flask 2 wascharged 1200 g of dodecyl alcohol (Kalcol-2098, manufactured by KaoCorp.), and then hydrogen gas was blown in at a rate of 20 L/h, the ratebeing calculated in terms of the standard state volume thereof, from thebottom of the separable flask 2 through a glass tube 6 having an outsidediameter of 6 mm and a thickness of 1 mm. The edged turbine 11 having animpeller diameter of 40 mm, illustrated in FIG. 5, was used to stir thesolution at a rotation number of 800 rpm while raising the temperatureof the solution. The position where the edge turbine was set up was aposition 1 cm apart from the downside of the catalyst layer 3.

The catalyst was subjected to reduction activation. Thereafter, whilethe flow rate of the hydrogen gas was maintained, dimethylamine gasstarted to be blown in through the glass tube 6. Furthermore, thetemperature was raised up to 220° C. The time when the temperaturereached 220° C. was decided as reaction zero time, and reaction wasstarted. The reaction pressure was set to normal pressure, and waterproduced by the reaction was continuously removed out of the systemthrough a rectifying tower. During the reaction, the stirring speed, thetemperature inside the system and the flow rate of the hydrogen gas weremaintained. The flow rate of the dimethylamine gas was made a constantvalue of 200 g/h before the amount of unreacted dodecyl alcohol turnedinto 10% as an area-percentage value analyzed by gas chromatography.When the value was 10% or less, the flow rate was lowered to 80 g/h asthe constant flow rate. Furthermore, at the time when the amount ofunreacted dodecyl alcohol was 10% or less, N₂ gas was supplied at aconstant rate of 48 L/h. During the reaction, the reaction was traced bythe above-mentioned gas chromatography. The yield of the productexcluding any byproduct when the amount of unreacted alcohol was 1% wasobtained from gas chromatographic data before and after this time. Theresults are shown in Table 1.

Comparative Example 1

A reaction apparatus illustrated in FIG. 8 was used to conduct thefollowing reaction.

Specifically, propeller blades 7 illustrated in FIGS. 6 and 7 were usedinstead of the edged turbine 1 in the reaction apparatus used in Example1 to disperse gas. Reaction was conducted through the same steps as inExample 1 except that the rotation number was set to 620 rpm so as tomake the stirring power equal to that of the edged turbine when hydrogengas was caused to pass at 20 L/h. In this case, the yield of the productexcluding any byproduct when the amount of unreacted alcohol was 1% isshown in Table 1. The byproduct was generated in a larger amount than inExample 1. Consequently, the yield was low. TABLE 1 Example 1Comparative example 1 Alcohols as starting material Dodecyl alcohol 1200g Dodecyl alcohol 1200 g Reaction temperature 220° C. 220° C. Kind ofcatalyst Film-formed catalyst of Film-formed catalyst of Productionexample 1 Production example 1 Weight of film-formed catalyst 5.6 g 5.6g (including binder) Catalyst arranging Doughnut form Doughnut formmethod ø 130 mm/ø 80 mm ø 130 mm/ø 80 mm Gas dispersing method Glasstube ø 6 mm + Glass tube ø 6 mm + Edged turbine Propeller bladesRotation number 800 rpm 620 rpm Power 0.0698 kg · m²/s³ 0.0698 kg ·m²/s³ H₂ flow rate 20 L/h 20 L/h Flow rate of dimethylamine 200 g/hconstant when an 200 g/h constant when an unreacted alcohol amount ismore unreacted alcohol amount is more than 10% than 10% →80 g/h constantin the unreacted →80 g/h constant in the unreacted alcohol amount of 10%or less alcohol amount of 10% or less N₂ flow rate 48 L/h constant inthe unreacted 48 L/h in the unreacted alcohol alcohol amount of 10% orless amount of 10% or less Yield*¹ 90.0% 87.6%*¹content of pure N-dodecyl-N,N-dimethylamine

1. A reaction apparatus for conducting a gas-liquid chemical reaction inthe state that the liquid forms a continuous phase, provided with afilm-formed catalyst and a shear type stirring impeller for dispersing araw reaction gas or a carrier gas.
 2. The reaction apparatus accordingto claim 1, wherein the shear type stirring impeller is a concaveturbine or an edged turbine.
 3. The reaction apparatus according toclaim 1 or 2, wherein the reactor has therein an inducement baffle forthe raw reaction gas.
 4. The reaction apparatus according to claim 1 or2, wherein the gas-liquid reaction is a reaction for producing atertiary amine from a primary or secondary amine and an alcohol.
 5. Aprocess for producing a tertiary amine, comprising the step of reactinga primary or secondary amine with an alcohol, in a reaction apparatusprovided with a shear type stirring impeller, by conducting a gas-liquidchemical reaction with a film-formed catalyst in the state that theliquid forms a continuous phase, dispersing a raw reaction gas or acarrier gas with the impeller.
 6. The process for producing a tertiaryamine according to claim 5, wherein the alcohol is a linear or branched,saturated or unsaturated aliphatic alcohol having 6 to 36 carbon atoms.7. The process for producing a tertiary amine according to claim 5 or 6,wherein the primary or secondary amine is a primary or secondaryaliphatic amine to react with an alcohol.